Tremolo mechanism.



B. R. VAN VALKBNBURG.

TREMOLO MECHANISM. APPLICATION FILED JULY 26, 1912.

1,085,308, Patented Jan. 27, 1914.

2 sums-sum 1.

IN I/ENTOR WITNES E8. 47% 507? R. Van Val/(62mg COLUMBIA PLANDGRAPH CO..W1\SH'1NGTON.D. c.

B. R. VAN VALKENBURG.

TREMOLO MECHANISM.

APPLIGATION FILED JULY 26, 1912.

1,085,308. Patented Jan. 27, 1914.

2 sums-sum 2.

INVENTOR Burt H. Van Vallrenbu ry 2 9 WITNESSES:

BURT R. VAN VALKENBURG, OF OAKLAND, CALIFORNIA.

TREMOLO MECHANISM.

Specification of Letters Patent.

Patented Jan. 27, 1914-.

Application filed July 26, 1912. Serial No. 711,635.

To all ill/1.07% it may concern:

Be it known that I, BURT R. VAN VAL- KnxnUno, citizen of the United States, residing at Oakland, in the county of Alameda and State of California, have invented certain new and useful Improvements in Tremolo Mechanisms, of which the following is a specification.

This invention relates to musical instruments of the type used in connection with perforated music sheets and has special reference to a means for producing a tremolo effect in connection with such instruments.

The principal object of the invention is to provide a novel form of valve for use in connection with instruments of this class so arranged that the same may be opened and closed repeatedly in a rapid manner thereby actuating the musical instrument to produce a tremolo effect such as is employed in beating a snare drum, producing an imitation of the vox humana stop in connection with a set of organ pipes.

WVith the above and other objects in view. the invention consists in general of certain novel constructions, combinations and arrangements of parts as will be hereinafter fully described illustrated in the accompanying drawings, and specifically claimed.

In the drawings-Figure 1 is a front elevation of a player piano partly broken away showing the device used in connection with a drum mounted on the top of the piano. Fig. 2 is a cross section through a valve used in connection herewith. Fig. 3 is a valve which is located on the key slip of the piano for controlling the valve shown in F 2. Fig. 4: is a rear elevation of the tremolo device. Fig. 5 is a front view with the cover plate removed. Fig. 6 is a transverse section through the tremolo device.

The casing of the piano used herewith is indicated at 1,0 and this piano is of the ordinary player type, the mechanism of which it is not deemed necessary here to be shown as the same forms no part of the present invention. The casing is provided with the usual key slip 11 and on top of the piano there is located a drum 12 in front of which is positioned a tremolo device indicated in general at 13. This tremolo device 13 consists of a bellows having a stationary side 14 firmly fixed in position on the top of the piano and to this stationary side is hinged a movable side 15, the two sides being connected by suitable flexible walls 16.

Extending through the side 11 is an opening 17 on each side whereof is located a bridge plate 18 and each of these bridge plates is provided with openings 19 for the passage of air. 'llhrough the bridge plate 18 extends a valve stem 20 and on this stem on the outside of the casing is a valve 21. In order to limit the movement of the valve in an outward direction there is provided a stop member 22. Secured to the sides oi. the bellows is a spring which normally holds the bellows in an open position and within the bellows there is provided a leaf spring 21 which has one end secured to the movable side 15 adjacent its hinged wall; the other end projects over the end of the valve stem 20. The position of this end with relation to the valve stem 20 when the bellows is distended is regulated by means of an ad justing screw 25 while the extent to which the bellows will collapse is regulated by means of an adjusting screw 26 which passes through the movable side of the bellows and bears against the spring adjacent. the valve stem 20 when the bellows is collapsed.

Secured to the movable side 15 is a drum stick 27 provided with a head 28 adapted to contact with the sheep skin covering the drum. This bellows is connected by means of a pipe 29 to a valve box 30 which is provided with a chamber 31 connected by means of a pipe 32 with a source of vacuum 33, the specis'ic means not being deemed necessary here to be shown as the same forms no part of this invention. Leading from this chamber 31 to the open air is a passage 31; and the pipe 29 communicates directlywith this passage and by means of the passage with the chamber 31. On each side of the opening 3:." is a bi plate 35 similar to the bridge plates lb and through these bridge plates passes a valve stem 36 carrying be tween the plates a valve 37 arranged to close either end of the opening 34:.

Extending from the chamber 31 is a cell 38 which is cut off from the chamber by means of a flexible diaphragm 39 against which the lower end of the valve stem 36 bears. Connected with the cell 38 are passages 10 and 41; the passage 4:0 is connected by means of a tube 42 with a tracker board forming part of the automatic playing mechanism. The passage 11 is connected by a tube 14 with a valve box 45 having an opening 46 with which the tube is connected and this opening is normally held closed by means of a valve L7 carried on a lever l8 which is constantly urged in the direction of the opening e6 by a spring This valve box lo is located beneath the key slip 11 of the piano and extending upward through the slip is an operating button which controls the opening and closing of the valve ife, being connected at its lower end to the lever 4:8.

In the operation of this device whenever pressure is reduced in the cell 38 by means of opening one of the passages 40 or ll. to the air either through the medium of an opening in the music sheet as indicated at 51 or by opening the valve l6 the valve 37 will. close the outer end of the opening 3iand open the inner end. This will place the interior of the bellows in communication with the vacuum device and when this is done the bellows will. collapse. i soon as the bellows collapses the spring 24: will strike the valve stem 20 and open the valve 2i. This will allow a rush of air under atinospheric pressure to expand the bellows innne diately upon which the valve 2t will clo'e and the vacuum will again operate to collapse the bellows. 'lhese alternate actions will take place with a rapidity depending on the amount oi? collapse that the bellows has so that they can. be regulated by positioning the screws 25 and 26 as they will also depend on the time in which the valve ill opens. Thus the drum stick 2? .vill be rapidly vibrated and the drum beaten. There has thus been provided a simple and ellicicnt device of the kind described, and for the purpose specified.

Having thus described the invention, what is claimed as new, is

1. In a device of the kind described, a fixed bellows side having an ope 151 "herethroi'igh, and a pass: ge adapted tor c-t tion to a vacuum tn e. an outward ing valve controlling said opening, a inov able bellows side hinged to the fixed side, a

1 OP till properly flexible wall coiniecting said sides, a stem on said valve pro ecting within the chamber formed by said sides and wall, havin one end connected ad acent the hinge a leaf spring of the movable side and the other end lying adjacent the valve stem, and means to adjust said sprin 2. In a device of the kind described, a fixed bellows side having an opening there through, and a passage adapted for connection to a vacuum tube, an outwardly opening valve controlling said opening, a inovable bellows side hinged to the fixed side, a flexible wall connecting said sides, a stem on s d valve projecting within the chamber 'lori'ned by said sides and wall, a leaf spring having one end connected adjacent the hinge ot the movable side and the other end lying adjacent the valve stem, means to adjust said spring, a screw passing through e aaid movable side and. bearing constantly against the spring, and a second screw passthrough said movable side and adapted for engagement by the spring when the latter st 'lliQS the valve stem.

in a device of the lnnd described, a

lixed bellows side having an opening there- ,1 a1

n-ough, and a passage adapted for connection to a vacuum tube, an outwardly opening valve controlling said opening, a mova le bellows side hinged to the fixed, side, a flexible wall. connecting said sides, a stem on said valve projecting within the chamber formed by said sides and wall, a leal? spring having one end connected adjacent the hinge of the inovaliile side and the other end lying adjacent the valve stem, means to adjust said spring, a screw passing through said movable side and bearing constantly against the spring, a second screw passing through said movable side and adapted for engagement by the spring when the latter strikes the valve stem, and. a spring connected to said sides and arranged to constantly urge he free end of the movable side away vtroin lixed side.

11 testimony whereof .l ailix my signature )resence of two witnesses.

BURT R. VAN VAUKENBURG.

. Soiinonenn, il ii. Sroon.

Gepies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. C. 

